Searchlight control mechanism



Nov. 19, 1935. H. G. FRENCH 2,021,720

' SEARCHLIGHT CONTROL MECHANISM Filed Nov. 15, 1935 s Sheets-Sheet 1 75 LOCAL CONTROL HAM:

CONTROL Inventor Henna G .Ffencn His Attorney.

Nov. 19, 1935. H. G. FRENCH 2,021,720

SEARCHLIGHT CONTROL MECHANISM v Filed Nov.. 15, 1953 5 Sheets-Sheet 2 Inventor: Henry G French, 109 7 His tforneg.

Nov. 19, 1935, H. G. FRENCH 2,021,720

SEARCHLIGHT CONTROL MECHANISM Filed Nov. 15,1935 3 SheetsSheet s (saw by His Attorney.

Patented Nov. 19, 1935 snancmonr con-moi. mcnamsn Henry G. French, Schenectady, N. 1., assignor to a General Electric Company,

New York a corporation of,

Application November 15,1933, Serial No. 698,091

iocioina. (or. 240-614) My invention relates to operating mechanisms and more particularly to operating mechanisms for searchlights in which the searchlight may be operated either automatically by an electric motor or by hand from a control station located at a distance from the searchlight which is invisible to the operator.

One object of my invention is to provide animproved operating mechanism which may be easily changed from automatic motor operation to hand operation.

Another object of myinvention is to provide an improved operating mechanism wherein the actual position of the searchlight is indicated to the operator'at the hand control when that hand control is in use.

Another object of my invention is to provide an improved clutch mechanism whereby the hand control may be connected to the searchlight in the exact relationship at which it was disconnected so that the indicator, operated from the hand control, indicates the actual position of the searchlight when the hand control is operativelyconnected to the searchlighte I For a consideration of what I believe to be novel and my invention, attention is directed to the following specification, the accompanying draw ings and the appended claims.

Fig. 1 of the drawings illustrates diagrammatically a searchlight control mechanism bu flt in accordance with my invention. Figs. 2, 3 and 4 illustrate sectional views of the clutching mechanism built in accordance with my invention for use in the control system shown 3 in Fig. 1.

Figs. 5 and 6 illustrate one modification of the clutch mechanism, and Fig. 7 illustrates another modification.

In Fig. 1, a searchlight drum it is mounted on arms II and I! for movement in a vertical plane about trunnions i3 of which only one is shown. The arms ii and I2 are integral with a ring gear i5 which may be rotated about}; vertical axis by a gear i6 and a shaft l6. Movement of the 4 drum about its trimnions i3 is obtained by a worm gear i1 attached to a trunnion "and a worm l8 operated by a shaft i9. The shaft i9 is driven by a shaft 20 through a pair of bevel gears and the shaft 20 is driven through a differential 2| and a pair of concentric vertical shafts 22 and 23 rotated in opposite directions through gears 24 and 25, by a shaft 26. The shafts 22 and 23 are rotated in oppcsite directions at equal tively to the idler speeds and are connected res gear spider 2| and one of the planetary gears II" of the diflerential II. The secondplanetary gear 21' of the differential is connected to the shaft 20. In operation therefore the first planetary gear 2!" and the spider 2| being driven A in opposite directions at the same rate, transmit i a rotation to the second planetary gear 2i and the shaft 20 which is one half that of either the gear 2!" or the spider 21' due to the inherent construction of a differential mechanism. Simul- 4 taneously-this rotation is transmitted to the 10 shaft 20 in sucha manner that the horizontali paratus for driving shaft 20 by the'shaft 26 is the subject of my application, Serial No. 677,208, 15 flied June 23, 1933, and is fully described and claimed therein. The control'mechanism' for moving the shafts it and 28, and thereby the searchlight drum i0, includes motors 21' and 28. .The motor 2] i520 'gearedto a clutch member '29 by a worm 30 and a worm gear 3|. It operates a second clutch member 32 and'the shaftit' through a sleeve 33' and a pair of gears II and 35 when the clutch members 29 and 32 are in engagement; The mos5 tor 21 thereby controls the horizontal position of the searchlight or, in other words. the traverse. Motor 28 operates. a clutch member 36 through a worm 31 and worm gear-u and 'a second clutchmember 39', when the clutch members 36 and. so are in engagement with each other. The clutch member 39 is attached to a sleeve 40 and drives the shaft 28 through a pair of gears II and 42. Themotor 28, therefore, controls the position'of .the searchlig'ht in a vertical plane, or in other 35 words its elevation. The motor controls are supplemented by hand 1 controls which are located within the ship from v where the operator cannotsee the searchlight thereby when these clutch members-are .in engagement. This shaft is connected to drivethe sleeve I; and gear 34 only when the hand 'opso oration clutch meinbers'fland 53 are .in -eneasement with other. The'shaft Iii is furthermore connected to drive an indicator through a shaft li'and speed-reducing gearswl and I1. Thisindicator is so'gearedtothe'shaft 66" II that it follows the exact movement of the drum about its axis. The indicatontherefore makes a complete revolution about its dial when the drum I makes a complete revolution. Since the shaft cannot follow the movements of the searchlight during the time that motor control, or local control, is used, it is necessary to reconnect the hand control to the searchiight at the-same relationship of the hand control and the searchlight so that the indicator will indicate correctly the position of the searchlight. For this purpose the hand operation clutch members 52 and 58 are brought into engagement with each other only when the proper relationship of the searchlight and the indicator exists, although it may take several revolutions of the clutch members with respect to each other before such relationship-is reached. The clutch mechanism built in accordance with my invention. to obtain the desiredresult, is clearly shown in Figs. 2, 3 and 4 and modifications thereof are shown in Figs. 5, 6 and '7.

For controlling the elevation of the searchlight by hand, a second control station 58, similar to station 48, is provided. From this control station the elevation of the Searchlight -'is controlled through worm 59, worm gear 80, shaft 8|, bevel gears 82 and 63, clutch members 84 and 85, and shaft 88. Shaft 66 drives. shaft 28 through hand operation clutch members 81 and 88 when the two members are in engagement.

"I'his clutch is a duplicate of the clutch 52-53 and=will be described later in the specification.

An indicator I0 driven by the shaft 88 through Speed-reducing gears "-12 and shaft 13 indicates upon a dial the movement of the drum I0 in elevation when the hand operation clutch 81- 88 is closed. The drum is not capable of making a complete revolution in a vertical plane and the indicator dial in this case is accordingly marked. This shaft, similar to shaft 5|, is not operated when the searchlight is operated by the motor 28.

For the purpose of properly closing and open ing the various clutches, a selector handle v15 is provided. In Fig. 1 the selector handle is shown as being in its mid position at which all the clutches are opened. This position is used when it is desired to manipulate the searchlight drum directly, that is, push the drum'about its axis by hand. This operation is for convenience referred to as local control.

when the selector handle 15 is moved. toward the left the disc 18, upon which handle 15 is mounted, and a shaft 11 to which the disc is attached. are turned toward the left. By this op eration the motor operation clutches 29-82 and 88-88 andthe local control clutches 49-50 and 84-85 are closed, whereas the hand operation clutches 52-58 and 81-88 remain open. The local control clutches 48-50 and 84-85 are respectively operated by bell cranks 18, I9 and the operating rods 80 and 8| connected between the "and the respective bell cranks "and 19.

e rods 80 48-50 and 84-85 by movin Fig. 1, open the clutches in: the bell cranks about their respective pivots to disengage the clutch members. When the handle 15 and thereby the disc I8 is moved either: to the motor control position at the left, or to the hand control position at the right, the rods 80 and 8|. are drawn away from the shafts 5| and 88, the bell cranks 18 and 19 are turned about the respective pivots, and the clutches attached thereto, in a counterclockwise direcshaft 88. A collar II 5 48-50 and 84-85 are closed. The closing of thelocal control clutches when motor operation is used doesn'ot efl'ect operation since, as stated above, the shafts 5| and 88 do not move during motor operation. 5 As stated before, the selector shaft 11 is moved with the disc 18. Shaft 11 is geared to a cam shaft 82 through gears 88 and 84 and moves this shaft and tw n cams 85 and 88, which are tion for motor control and clockwise for hand control. The cams 85 and 88 are provided with notches 85' and 88, respectively.. When. the handle is moved to the left for motor control, the cams are moved counter-clockwise until rollers 81 and 88, which roll on the cam surfaces, ride into the notches respectively. This permits arms 80 and 8|, which are respectively pivoted at 52 and 8 8 to raise the clutch members 82 and 88, due to the pressure of springs 20 84 and 85 respectively, until they are in engagement with the clutch members 28 and 88. The motor 21 is thereby connected to drive shaft I8, the connection being worm 80, worm gear 8|, clutch 29-82, sleeve 88 and gears 84 and 88. The 25 motor 28 is connected to drive the shaft '28 through worm 81, worm gear 88, clutch 88-88, sleeve and bevel gears 4| and 42.

Thehand operation clutches 52-58 and '81- 88 are operated by a'pair of arms I80 and Ill, 30,

handle 15 is moved to the motor control position, 40

whereas the cams 85 and 88 move counter-clock wise. Notches I02 and I08 are accordingly so placed that when the handle 15 is moved to the left or the motor control position, the notches I82 and I08 are moved clockwise and away from rollers H0 and III whereby the clutches 52-58 and 81 and 88 remainopen. When the handle 15 is moved to the right or. to the hand' control position, the cams I02-and I08 move counter-clockwise and the notches I82 and I88" 7 move into position to receive the rollers III and III whereupon the springs H2 and H8 force the arms I00 and IOI upward respectively about their respective pivots Ill and III. .The clutches will not close, however, until the in- 55 'dicators 54- and 10 indicate the proper position of the .drum I0. At this movement of the bandle 15, thenotches 85' and 88' are moved away from the rollers 81 and 88 whereby the motor clutches 28-82 and 88-88 remain open.

. The motor clutch 88-88 andhand'operation clutch 81-88 are shown in detail in Figs. 2, 3 and 4. As stated before, the clutches 28-82 and 52-88 are duplicates of the clutches 88-85and 81-88 respectively. Fig. 2 is a vertical sections] view through the center of the clutch mechanism. This view illustrates the clutch members 88-88 and 81-88 in the open position. The arms 8I- and III for operating the clutch members 88 and 81.

respectively, are not shown. The entire mechaeanr centered about" the pinned'to the shaft by a pm I" prevents axial displacement of.the parts along this shaft I As shown in m. i the com :1 engages a d nism is supported by drives the worm wheel 38. Worm wheel 38 is freely rotatable about a sleeve 46 and is provided on its under side with a series of clutch teeth comprising the clutch member 36. This worm wheel is prevented from axial displacement by a flange IIB integral'with the sleeve 46 and. by a collar 6 attached to the sleeve 46 by a set screw III. The sleeve 46 is free to rotate about the shaft 66 when the clutch members 61 and 68 are disengaged, and is movable about the shaft irrespective of the engagement or disengagement of the clutch members 36 and 38.

The gear 4| which, as above explained, drives the elevating mechanism for the drum is keyed to the sleeve 46 by a key I22 and the clutch member 38 is keyed to the sleeve by a key #23, but is axially movable into and out of engagement with the clutch member 36. By this arrangement, therefore, the motor 28 through worm 31, worm gear 38, clutch members 36-36, sleeve 46 and gear 4| can control the elevation of the searchlight drum I6. The shaft 66 during such operation remains dormant and the indicator 16, therefore, does not follow the position of the drum.

When hand operation is desired, the selector handle 15 is turned to the right whereby the clutches 64- 65 and 61-68 areset for closing as soon as the proper relation between the cooperating members thereof is reached. The

clutch member 66 is'keyed to the shaft 66-and rotates therewith and the member 64 is geared to the operating wheels 58 so that to close this clutch it is only necessary to turn the clutch member 64 a fraction of a revolution until its slots are in line with the teeth on the member 65 to close this clutch. Before the clutch members 61-68 may be engaged, however, the shaft 66 will need to be rotated several revolutions until the indicator 16 indicates the correct position for the drum I6.

' The clutch member 66 comprises a ring which is attached to the sleeve flange II8 by bolts I24. This member of the clutch, therefore, follows the movement of the drum since the sleeve 46 and gear 6| are always connected to it irrespective of the arrangement of the clutches.

The clutch member 61, on the other hand, follows the movement of the shaft 66. This is accomplished by a disc I26, keyed to. the shaft 66 by a key I21 and provided with tapered holes 826 into which thepins I29, attached to the clutch member 61, project. A loose connection is thereby formed between the disc I26 and the clutch member 61 which, due to the taper on pins i26, becomes a rigid connection when the clutch is closed.

The clutch members 61 and 68 are..prevented from closing, until a proper relation between drum position and indicator is reached by a locking disc E36 which is free to rotate about the shaft 66. This locking disc I36 is provided-with a series of downwardly-projecting pins I3I which are annularly arranged about the center of the disc and at such radius as to project within the clutch member 68,'which as above stated is in the form of a. ring and is attached to flange II8. There are in the present embodiment of the invention thirty pins equallyspaced.

Between thelocking disc I36 and the flange II 6, the shaft 66 is provided with a circular cam I82 which is eccentrically mounted with respect to shaft 66 and is better illustrated in Figs. 3-' and 4. About the cam I32 and rotatable with respect toll; is a gear I33 provided, with 27 teeth.. This gear is of such diameter that the gear teeth engage the pins at the point at which the cam is at the greatest distance from the center of the shaft. The gear is prevented from rotating'with respect to the clutch member 68 by a pin I 34 projecting from flange II8 into a slot on the under side of the gear. By this arrangement the teeth of the gear successively engage the pins as the cam I32 and the shaft 66 rotate with respect to the clutch member 68.

Due to the fact-that there are only 27 teeth in the gear and there are 30 pins in the locking disc I36, the locking disc is given a rotational movement with respect to the clutch member 68. This may be readily understood when considering the pins I3I as constituting an internal gear. Since there is a difference in the number of teeth of the two engaging gears, there will be a difference in the rotative movement of the two gears about their common axis. In the present case I the gear I33, being pinned to a flange II8, can-'20 not rotate with respect to the clutch member 68, but the locking disc is rotated with respect-thereto a fraction of a revolution proportional to'the.

difference in the number of teeth or one-tenth. of a revolution. This fact is made use of, to pre-. vent the engagement of the clutch membersj 61--68 when the shaft 66 with the indicator and the gear 4! with the drum I6 are not in a predetermined position with respect to each. other... The clutch member 68 is provided with two slots I36 spaced diametrically opposite each other on the edge of the .clutch member 68, into which 1 the prongs I31 mounted on the circumference ofthe clutch member 61 are arranged. to. project;

when the member 61 is lowered. The member. V

68 is also provided-with a. radial slot I38 extending inwardly from the edge of the clutch mem ber. This slot is shaped to accommodate asteel ball I46. The disc I36 is similarly provided with a radial slot I. When the two slots are direct-. 40 ly above each other, the weight of :the clutch." member 61 assisted by the spring pressure-upon. the lever arm I6I forces the ball I46, into the slots I38-I4 I, which, when in that'position',:form-- held in position by the ball. V When, during operation, the clutchmember 61.

a tubular chamber, the two halves of-which arej is lifted, theshaft 66, disctl26-andtthe clutchmember begin to rotate with respect to the. I

clutch member as. The slot n inthejdisc 130,50

respect to each othentheball whichremains v in the slot I38 in the .clutch member-168, {will merely roll and willoifersubstantiallgno .fric-; tional resistance. As. already stated, the disc,

'I36 revolves at Ya speedfequal to. one-tenth of that of the shaft 6|. When the searchlight-drum 65 and the indicator become out of synchronism,-- it is not only necessary to return-theclutch members 61 and 68 into angular. relation within one revolution of each other, but it is necessary,

to turn the shaft as with the disc I26and am n-.10

member 61 until the-total angulardistancawhi; it traveled away from its original.positionwith respect to the position at which the clutch61 66 was opened, is eliminated.

. By this arrangement, therefdre. the clutch I members 61 and 68 may revolve with respect to each other several revolutions and cannot be reengaged merely "by moving the prongs I31 above the slots I36. The clutch members 61-68 must be revolved until the locking disc is brought into the position. at which the slot MI is directly above slot I38 and the ball I40 is enabled to move into the channel, thereby provided, and out of the way of the clutch member 68. A casing comprising members I42 and I43 partially encloses the clutch mechanism. It provides a support for the pivots 93 and. H5 of the arms 8| and I 0|. Roller bearings I44 and I45 provide a guide for the shaft 66 through the casin I42--I43.

Fig. 5 illustrates a modification of the clutch shown in Figs. 2, 3 and 4. In this modification the shafts I and I5I are to be connected to each other when the proper angular relation exists between them; that is, the exact relationship at which the two shafts were disconnected. In this modification the shaft I50 haskeyedthereto one clutch member I52 by a key I53. A second clutch member I54 is keyed to the shaft I5I by a key I55. This member is slidable along the shaft I5I into and out of engagement with the clutch member I52.

The clutch member I 54 is provided with a pair of power-transmitting fingers I56 and a guiding finger I51. The guiding finger normally projects partly into a radial slot I58 in a bushing member I 53. This bushing member I 59 is free to rotate about the clutch member I52. not move axially with respect to this clutch memher because of pins I60 which project into a circular slot I6I in the clutrh member I52 at one end and into slots I62 in a ring gear member I63 at the other end. This ring gear member is in effect a worm and engages a worm gear I64.

The worm gear I64 is mounted on a horizontal shaft I65 to which a bevel gear I66 is attached. Bevel gear I66 engages a bevel gear I61 mounted on a vertical shaft I68. Both shafts I65 and I68 are mounted for rotation in bearings located in a bracket I10. A pinion I1I is attached to the other end of shaft I68 and is arranged to engage the gear teeth on the rim of a locking ring I12. This entire assembly is enclosed in a casing I13 which is attached to, and rotates with, the clutch member I52. The particular means for attaching the casing I13 to the clutch member I52 is set screw I14 and nut I15. The bracket I10 is attached to the casing I13.

In operation when the clutch members I52 and I54 are separated the shaft I50 drives clutch member I52, casing I13, bracket I10 and therefore the worm gear I64. The shaft I5I, on the other hand, drives clutch member I54, bushing I58, worm ring I63. The shaft I5I is prevented from axial displacement by a split ring I16 which fits into a circular slot near the end of the shaft and projecting beyond the surface of the shaft. The ring fits into the clutch member I52, being locked therein by a bushing I11 which; is held in place by a screw I18. The ring I16 is so arranged that shaft I5I may, of course, rotate with respect to the clutch member I52 when the clutch members I52 and I54 are separated.

. In operation, when the clutch members are disengaged,the slots I80, I58 and I8I in the members I52, I59 and I12, respectively, are out of alignment. As above explained, the clutch members I52 and I54 being attached respectively to their shafts I 50 and I5I rotate with respect to each other and therefore the fin ers I56 on It canthe clutch member I54 are out of line with slot's I82 in the clutch member I52. Furthermore, finger I51, which drives the bushing I58 through the slot connection I58, causes the disalignment of the slots I and I58. With the construction so far considered, it would be necessary to-tum the shafts I 50 and I 5| not more than one rev.- olution to permit the reengagement of the clutch members. This is undesirable, however,z since due to various gear reductions the shafts may be out of alignment several revolutions, For this reason the worm ring I63 being'driven from shaft I5I, as above explained, rotates with'respect to the worm gear I64 which is driven'from shaft I50 through the casing I13 and bracket I10 15; and thereby transmits, through gears I66, I61 and III and the shafts I65 and I68, a movement to the bushing I12. This movement causes the disalignment of slot I8I in the bushing I12 with respect to the slots I80 and I58. 6 y The finger I51 is made of such dimensions that the engagement of the clutch members istmpos-- sible unless all three slots are in alignment.- The speed reduction between the worm ring I63 and the bushing I 12 can be made relatively large '25. since the worm and worm gear are employed. The ratio is of course dependent upon the gear ratios used in other parts of the apparatus. If; therefore, in operation the shafts are moved more than one revolution away from each other, 0 the clutch cannot be closed until this angular distance is eliminated either by turning the shafts back to eliminate the angular distance and bringing the bushing I12 back to its original position or forward to complete a revolutionwof 3 the bushing I12. e a

Fig. 7 is another modification of my clutch mechanism in which a locking member 200 is driven by one of the clutch members 20I through a set of reducing gears comprising solelyispui' 4!). gears. In this modificationthe shafts 202 and 203 are connected by clutchmembers 204 and 20!, 204 being slidable along the shaft 202. When the clutch members are disengaged shaft 202 drives clutch member 204 and a casing 205 i}. which is keyed to this clutch member by a'key 201. The shaft 203 drives the clutch member 20I, a gear 208, a bushing 209, the locking ring 200 and a ring gear 2I0. The bushing 208 and clutch member 20I are keyed to the shaft- 203 .0. by keys 2 I2 and 2 I3. When the shafts rotate with respect to each other, the gear 208 rotates with respect to the casing 205 and thereby transmits motion to the gears 2I4, 2l5, 2I6, shaft 2I1, which revolves in bearings attached to the casing 5' 205, gears 2I8, 2I9 and 2I0. The locking ring 200 is thereby rotated and a .ball 22I similar to the ball I40 of Fig. 2 is forced into the..path of the clutch member 204 preventing its engage ment with the clutch member 20I. The ball .0: rests in a slot 222 in the clutch member 20]. .41 short slot 223 in the locking ring 200 enables the ball 22I to be forced into the path-of the clutch member 204 when the latter is lifted.

The ratio of transmission between gear 208 5-: and the locking ring 200 through; gear 2I0 .is again such that several revolutions are permitted between the shafts before the locking ring makes a complete revolution and therefore returns to its original position. In order that the clutch 7;); members may engage each other, it is necessary to turn the shafts until the clutch members and the locking ring are in the proper position. What I claim as new and desire to secure by Letters Patent of the United States is: i

1. In a searchlight-control mechanism, the combination of a searchlight mounted for movement about air axis, an electric motor arranged to move said searchlight about said axis when connected to said searchlight, manualcontrol means for moving said searchlight about said axis when connected thereto, an indicator operated by said manual-control means for indicating the position of said searchlight, and.

clutching means operable to connect said motor and said manual-control means to said searchlight alternately and arranged to connect said manual-control means to said searchlight only when said indicator indicates correctly the position of said searchlight.

2. In a searchlight-control mechanism, the combination ofa searchlight mounted for adjustment about a vertical and a horizontal axis, electric motors for adjusting said searchlight about its axes, manual-control means for adjusting said searchlight about its axes, indicating means operative by. said manual-control means to indicate the position of said searchlight about its axes, and clutching means for alternately connecting said manual-control means and said motors to said searchlight and arranged to connect said manual-control means to said searchlight only when said indicating means indicates correctly the position of said searchlight about its axes.

3. In a searchlight-control mechanism, the combination of a searchlight adjustable about a horizontal and a vertical axis, automatic-control means for adjustingsaid searchlight about aid axes, manual-control means for adjusting said searchlight about said axes, indicating means operated by said manual-control means for indicating the position of said searchlight about both axes, clutching means, and a common control handle for connecting said automatic and said manual-control means to said searchlight alternately, said clutching means being arranged to connect said manual-control means to said searchlight only when said indicating means indicates correctly the position of said searchlight about both of said axes.

4. In a clutch mechanism, the combination of a driven member, a driving member arranged to normally rotate with respect to said driven member, means tor connectingsaid two memhere to each other substantially irrespective of the angular relationship between said members, a second driving member arranged to normally rotate with respect to said driven member, and means rotatable between said second driving member and said driven member for causing said two members to be connected only when the exact angular relationship exists at which they were disconnected.

5. In a clutch mechanism, the combination of a driven member and two driving members, said members being rotatable about a common axis, means for connecting one of said driving members to said driven member substantially irrespective of the angular relation between said two members, and means for connecting the second or said driving members to said driven member when the exact relationship exists at which the said two members were disconnected including a flocking disc arranged concentrically with and between said driven and second driving members, means for driving said locking disc including a circular cam eccentrically arranged with respect to said locking disc and rotatable with said second driving member, a gear surrounding said cam and non-rotatable with respect to said driven members, and a series of annularly arranged pins attached to and arranged concentrically on said locking disc and engaged successively by said gear when said second driving member and said driven member rotate with respect to each other, the number of said pins and the number of teeth in said gear differing from each other whereby said disc is rotated.

6. A clutch mechanism comprising a driven member, a driving member, means for moving said driving member into engagement with said driven member, means for preventing the engagement of said two members until a predetermined angular relation exists between them including a locking member arranged concentrically with and between said driven and driving" members and rotated at a speed proportional to the'difierence of rotation between said driving and driven members. h 7. A clutch mechanism comprising a driven member, a driving member, means for moving saiddriving member into engagement with said driven member, means for preventing the engagement of said two members until a predetermined angular relation exists between them including a locking member arranged concentrically with and between said driven and driving members and-rotated an angular distance proportional to the angular distance which said members turned 80' away from the engaging position.

8. In a clutch mechanism, the combination of a a driven member, a driving member, means for moving said members into, engagement with each other, means for preventing the engagement oi 85' said members until a predetermined angular relation exists between said members, including a locking member which is geared to said driven and said driving members and arranged to rotate in proportion to the angular distance that the 40 driven and driving members move away from the relationship at which they were disengaged whereby the said two members are required to return to the engaging position through several complete revolutions to eliminate the total angular distance traveled from the relative positions at engagement.

9. In a clutch mechanism, the combination of a driven member, a driving member, means for moving said members into and out of engages ment with each other and means for, preventing the engagement of said members until a prede termined angular relationship exists between them including a slot in said driven member, a floating member arranged concentrically with said driven member and rotatable in synchronisiil with said driving member, a slot in said floating membena locking member arranged concentricaliy with said driven member and rotated in proportion to the rotation between said driven and driving members, a slot in said locking mem'-, ber, and a guiding finger upon said driving member which holds said driving member out 01' engagement with said driven member until the slots in said driven, floating and locking members are in line with each other.

10. In a clutch mechanism, the combination of a driven member, a driving member, means for moving said members into and out of engagement with each other and means for preventing the engagement of said members until a predetermined angular relationship exists between them including a locking disc mounted Iconcentrically with said driven and driving memers,

means for driving said disc in proportion J I to the angular movement between said driving alignment for engagement, and means for forcing and driven members, a ball mounted between said ball into the path of said driving member said driven member and said disc, a pocket for and prevent its engagement with said drivsaid ball formed when said. disc, said driven memen member until such proper alignment exists.

5 her and said driving members are in proper HENRY G. FRENCH. 

